The present invention relates to an apparatus for transferring solids such as fish, hams and sausages by the use of a liquid as the transfer medium.
Presently, two methods generally are known for transferring solids which are easily damaged by the use of water as the transfer medium. One method employs a rotary pump system in which solids and water are passed through a rotating impeller in a bladeless pump or the like. The other method employs a static volume type transfer system in which the volume in a closed tank is reduced by a vacuum pump, and solids and solids and water are sucked through a nonreturn valve and a suction pipe into the tank and then discharged therefrom through a nonreturn valve and a discharge valve by the injection of compressed air.
The former method is efficient since solids can be continuously transferred. However, as the solids are passed through a centrifugal impeller rotating at a high speed, they are apt to be damaged. Further, if the least amount of air is sucked into the pump, the operation of the pump stops and the solids may be badly damaged.
The latter method is not efficient because of the batchwise operation in which the discharge action is stopped during the suction step and the suction action is stopped during the discharge step. If a plurality of closed tanks are provided so as to obtain a reversible operation in which one tank carries out the suction action with the other is carrying out the discharge action and then the reverse actions are carried out, the abovementioned inefficiency still cannot be overcome. The reason is that the operation must be stopped during the changing-over operation, and especially, the suction action cannot be started until the pressure in the tank is reduced to some extent.